So I'm spending another sunny day in the bilge and I'm looking forward to the completion of a long project. Diesel tank contamination. I've drilled inspection ports into the tank, pumped out the crud, (said goodbye to 40gallons of die$el) polished the tank, cleaned out the racor bowl and installed a new 10micron filter.

Now, I'm trying to install the engine mounted fuel filter and bleed. Before I installed the engine mounted fuel filter I checked the flow by manually operating the lift pump. I get 2 good squirts and then nothing but a drip. On the RACOR the vacuum guage goes up into the red as it won't pump anymore. If I wait a minute or two the vacuum gauge falls and it will pump one or two times again.

*#&%$*@ %*$&$!!!

Do I have a blockage in my fuel lines? (the only part I didn't change)?
Is there a restriction elseware?
Does the gauge going down indicate an air leak or slow flow under suction?

Help!

MedSailor

SteveInMD

07-09-2008 05:25 PM

Is the fuel shut-off valve open?

I find some hose and ball-squeeze-pump (like from and outboard motor) a very good fuel flow trouble shooting tool. Hook this to the pickup nipple and see if the pickup is blocked. If it isn't then move down the line to the Racor.

The gauge is telling you there is slow flow under suction.

MedSailor

07-09-2008 05:29 PM

There actually isn't a fuel shutoff valve.... reminds me that I need to install one.

Is it possible that the lines themselves are all gunked up? Where else could the restriction be?

I might give the outboard bulb thingy a try though the fittings are always a problem.

Back to the bilge.

Medsailor

SteveInMD

07-09-2008 05:52 PM

The most likely place is at the pickup base in the tank. It could also be at an elbow or connection. It could be in the middle of a fuel line, but it's unlikely.

Have you replaced your Racor filter? If you had bad fuel, you may have to replace it 2 or more times.

If you buy the right size hose, temporarily hooking up a ball pump should be quick and easy. Just push the hose on the nipple. Start at the tank, test each section, and move down the line until you isolate the problem.

Faster

07-09-2008 05:59 PM

There's a good chance that there was still crap in the lines following your tank cleanout, and that your 'new' filter is already plugged... simplest thing now is to change it. I'd flush all lines before reinstalling the next filter.

speciald

07-09-2008 06:21 PM

Could try blowing back through the line with something like an inflateable boat pump. Sometimes the screen on the pickup gets clogged. Don't know why they put that sccreen there anyway.

MedSailor

07-09-2008 07:01 PM

Thanks for the suggestions so far, they are really helping my troubleshooting.

In response the filter probably isn't clogged yet. I emptied out the tank completely, polished the inside to a mirror finish, changed the racor filter, polished the inside of the racor (though not quite as well) and poured clean recently bought fuel into the tank and racor directly. The problem happened immediately.

The bulb idea is a good one though my lines have swedged on compression fittings and are threaded on to the racor. No nipples.

I'll check the screen, lines and elbows now. Should have just replaced all the lines before I filled up everything but I forgot.:(

Medsailor

MedSailor

07-09-2008 07:23 PM

Found the problem! It was being caused by the new Racor vacuum gauge. I bought the T-handle adapter and gauge (genuine) Racor. At the recommendation of my lovely Admiral I changed it back to the original T-handle as it was one of the only things that changed and now it works.

Thanks for everyone's help. Now I have to bleed the thing.....

MedSailor

Stillraining

07-09-2008 07:59 PM

What is a T handel adaptor?

Gary1

07-09-2008 11:05 PM

The adapter is a widget that you use to put a vacuum gauge on top of the racor filter. The theory being that when the output side of the filter has too much vacuum on it, the filter is clogged. They work. I never had much luck with the o-rings they sent, though. Replaced them with a little fiber washer that I greased up liberally with vasoline.